Electronic components, such as integrated circuits, are often packaged by mounting them on a support, or substrate as it is sometimes known, and then encapsulating them in a block of resin.
The resin protects the component but is a thermal insulator. However, the integrated circuit (IC), or other electronic component, produces heat that must be removed from the package. In certain cases, for example, with complex system-on-chip IC's, the amount of heat produced is such that conduction through the resin and substrate are not enough.